1. Field of the Invention
The present invention relates to a liquid droplet jetting apparatus which includes a jetting head unit for jetting liquid droplets, and particularly to a cooling structure of a heat generating section of the liquid droplet jetting apparatus, and a structure which eliminates floating of fine liquid droplets (mist) which are generated when the liquid droplets are jetted from a nozzle.
2. Description of the Related Art
In a liquid droplet jetting apparatus such as an ink-jet recording apparatus, if there is a portion which generates heat at the time of jetting a liquid, the generated heat affects and destabilizes the jetting operation. Therefore, in U.S. Pat. No. 7,188,922 (corresponds to Japanese Patent Application Laid-open No. 2004-291342), a recording apparatus as a liquid droplet jetting apparatus, in which a heat sink is arranged being in contact with a driving circuit element (driver element) which generates a heat, has been described.
In Japanese Patent No. 2738697 (refer to FIG. 1 and FIG. 2), a liquid jetting head, which jets liquid upon bubbling by heat generation and in which a liquid is used for cooling down a heat generating substrate of a head, has been described. More elaborately, the entire head and the heat generating substrate are forcibly cooled down by flowing a liquid such as water in a liquid supply pipe in the form of a tube provided around the head, or in a hole provided in the heat generating substrate. Moreover, a structure, in which the heat generating substrate is formed of a porous member, and a liquid is allowed to be permeated in the porous member, and the heat is released by the heat of vaporization, has been described.
Moreover, in liquid droplet jetting apparatuses, it has hitherto been known that fine liquid droplets (mist) are generated at the time of jetting liquid droplets from a nozzle, and these fine liquid droplets contaminate an inside of the apparatus. In Japanese Patent Application Laid-open No. 10-765, a structure which recovers these fine liquid droplets (mist) has been described. Concretely, a recording head which jets an ink is installable, and a carriage which is reciprocatably movable, and a separating member for forming a channel for air which flows along with the movement of the carriage are provided in this liquid droplet jetting apparatus. Moreover, a filter which is capable of absorbing the ink in the air channel is provided. An air flow is generated inside the apparatus due to the movement of the carriage, and ink mist in the air flow is recovered by a filter.
In recording apparatuses, in recent years, high densification and high speeding-up of recording have been sought, and there is a tendency toward an increase in the number of nozzles which jet a liquid. When the recording is carried out at a high speed, in other words, when a liquid is jetted from a large number of nozzles at a high frequency, there is an increase in an amount of heat generated by a driving circuit element. The heat of the circuit element is transferred to the jetting head, and there is a possibility that the jetting operation is destabilized.